US4223700A - Flow line switch - Google Patents

Abstract

A flow line switch having a housing and a rotor mounted within the housing, an annular piston between the rotor and the housing and adapted to slide axially in the annulus between the rotor and housing, means for supplying and venting fluid to and from opposite ends of the annulus for movement of the piston, the rotor having a passageway extending therethrough adapted to connect to at least one port through the housing at one end and selectively to one of at least two ports at the other end and stop means at the extremities of travel of the piston to assure communication between the preselected ports.

Description

BACKGROUND

Flow line switches or diverters of the prior art have been subject to problems of leakage of fluid into the closed branch, of not having a substantially constant diameter flow passage and of requiring complex mechanisms for assuring simultaneous operation of two switches in the same flow system. In present day oil and gas production wells, TFL (through-flow-line) tools are used for controlling various functions. Flow lines for such tools should not have sharp bends and should have a uniform passage flow area to assure proper movement of such tools in the flow line.

The use of multiple coacting switches is encountered in many systems and in most of such systems each switch may have both out lines and return lines. In such systems, it is important that the switches function substantially simultaneously and have some type of mechanical interconnections to assure such functioning which interconnections are expensive and relatively unreliable.

Examples of such prior art structures are shown in the R. I. Kunz et al U.S. Pat. No. 3,826,539, the G. E. Lewis et al U.S. Pat. No. 3,674,123, the W. Brown U.S. Pat. No. 3,545,474, the H. Allen U.S. Pat. No. 2,749,082, the M. L. Barrett, Jr. U.S. Pat. No. 3,047,020 and the G. Larsson U.S. Pat. No. 3,146,033. The J. V. Pennington U.S. Pat. No. 3,780,756 discloses a switching device for TFL tools which is actuated by the passage of a tool through the switch.

Also known are actuators utilizing an annular piston surrounding a shaft, which is keyed to the piston by helical splines, rods or other means to prevent relative rotation of the piston, as shown in the J. C. Miller U.S. Pat. No. 2,936,737.

A further summary of diverters for TFL tools is set forth in the ASME publication entitled "Diverters for T.F.L. Tools" by Andre H. Drouin and John H. Fowler (69-Pet-4) from the ASME Petroleum Mechanical Engineering Conference at Tulsa, Okla. Sept. 21-25, 1969.

SUMMARY

The present invention relates to an improved flow line switch which is suitable for use with TFL tools.

The improved flow line switch includes a housing with a rotor mounted therein and an annular space surrounding the rotor within the housing in which an annular piston is positioned for movement responsive to pressure differentials created thereacross. The rotor provides at least one passage which is adapted to connect from at least one port in one end of the housing selectively to one of at least two ports in the other end of the housing, the rotor, the housing and the piston being connected so that axial movement of the piston rotates the rotor to switch the flow.

An object of the present invention is to provide an improved flow line switch which effectively prevents flow into the closed branch of the flow lines.

Another object is to provide an improved flow line switch for switching more than one flow line without having interconnecting linkages, gears or other mechanisms to assure substantially simultaneous switching.

A further object is to provide an improved flow line switch capable of handling TFL tools.

Still another object is to provide an improved flow line switch with a hydraulic actuator which provides equal force in either direction, uses equal volumes of hydraulic fluid in both directions and has suitable indexing to insure exact register of the passage through the switch with the inlet and outlet.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and advantages of the present invention are hereinafter set forth and explained with reference to the drawings wherein:

FIG. 1 is a plan view of the preferred embodiment of the flow line switch of the present invention.

FIG. 2 is a left hand elevation view of the switch shown in FIG. 1.

FIG. 3 is a right hand elevation view of the switch shown in FIG. 1.

FIG. 4 is a sectional view of the switch taken alongline 4--4 in FIG. 2.

FIG. 5 is a partial sectional view taken alongline 5--5 in FIG. 4.

FIG. 6 is a sectional view taken along line 6--6 in FIG. 4.

FIG. 7 is a longitudinal sectional view of a modified form of flow line switch.

FIG. 8 is a sectional view of the preferred piston for use in the switch shown in FIGS. 1 through 6 with the view being taken along line 8--8 in FIG. 9.

FIG. 9 is an end view of the preferred piston structure.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Flow line switch 10 shown in FIGS. 1-6 includeshousing 12,rotor 14 withinhousing 12 andannular piston 16 positioned for reciprocation in the longitudinally extendingannular space 18 betweenrotor 14 and the interior ofhousing 12.Housing 12 includestubular body 20 andend flanges 22 and 24 which are suitably sealed tobody 20. Studs 26 andnuts 28 holdflanges 22 and 24 onbody 20.Body 20 has acentral bore 30.Flanges 22 and 24 have a plurality of ports, hereinafter described in detail, for communication to and from the flow line switch.

Therotor 14 includes thetubular shell 32,end plates 34 and 36 welded or suitably secured toshell 32 andcurved tubes 38 and 38' which form passages fromports 40 and 40' inend plate 34 toports 42 and 42' inend plate 36. The exterior ofshell 32 hashelical splines 44 which mate with thesplines 46 onpiston 16. The interior ofbody 20 hashelical splines 48 which mate with thesplines 50 on the exterior ofpiston 16. The piston includes means such as resilient rings for sealing against thesplines 44 and 48. Piston 16 includesbody 16a,sealing rings 16b,follower rings 16c, andcap screws 16d threaded into one offollowers 16c withsprings 16e between the screw heads and theother follower 16c to retain the components as an assembly.

Hydraulic fluid for operation ofpiston 16 is delivered to opposite ends ofannular space 18 throughpassage 52 inend flange 22 andpassage 54 inend flange 24. When hydraulic fluid is delivered throughpassage 52, the hydraulic fluid on the other side ofpiston 16 is vented throughpassage 54.Splines 44 to 50 provide a means for rotatingrotor 14 responsive to the movement ofpiston 16. It is preferred that thesplines 44, 46, be a helix of 40° in one direction and thesplines 48, 50 be a helix of 40° in the opposite direction. Thus, movement ofpiston 16 causespiston 16 to rotate becausebody 20 is held stationary. The movement ofpiston 16 causesrotor 14 to rotate in the same direction at twice the rate ofpiston 16. Different splines may be used, such as having the splines 48-50 extend parallel to the axis of thehousing 12, provided that sufficient rotation ofrotor 14 is achieved from its available movement to properly positioncurved tubes 38 and 38'.

The positioning ofrotor 14 to assure proper registry of theports 40 and 42 inend plates 34 and 36 withports 56 and 56' inend flange 22 andports 58, 58a, 58b and 58c inend flange 24 at each end of the stroke ofpiston 16 is provided by thepin 60 which is secured inend flange 22 and extends intogroove 62 inend plate 34. Whenpin 60 engages the end ofgroove 62 further rotation ofrotor 14 is prevented. Thus groove 62 is designed so that it ends in the proper position to causerotor 14 to be in the desired position at the end of each stroke ofpiston 16.

Each ofports 56, 56', 58, 58a, 58b and 58c is provided with avalve seat assembly 64 which is adapted to engage the face ofend plates 34 and 36 and when the ports are in registry to provide a seal around the ports.Counterbore 66 andgroove 68 are provided around the ports inend closures 22 and 24. The valve seat assembly includestubular sleeve 70 having outwardly flaringflange 72,spring 74 which is positioned betweenflange 72 andshoulder 76 formed bycounterbore 66 andseal ring 78 positioned ingroove 68.Springs 74urge sleeves 70 against the outer surface of end plates to prevent bleeding of substantial quantities of the fluids flowing through the flow line switch into the interior ofhousing 12. Some leakage is to be expected particularly during rotation ofrotor 14. To equalize pressure across the ends ofrotor 14, vents 80 extend throughend plates 34 and 36.

Dual seals 82 and 84 are provided at each end ofrotor 14 to seal betweenrotor 14 and the interior surfaces 86 ofend closures 22 and 24.Groove 88 insurface 86 extends completely aroundrotor 14 andpassageway 90 communicate fromgroove 88 to the exterior ofhousing 12 to assure the piston actuating fluid is not transmitted to the interior ofducts 38 or the ports.

Inoperation switch 10 is presumed to be in the position shown in FIG. 4 so thattube 38 connects fromport 56 toport 58 and tube 38' connects from port 56' toport 58a.Pin 60 is positioned in the end ofgroove 62 as shown in FIG. 6 andpiston 16 is in its far right-hand position. Movement is started by supplying a motive fluid such as an oil or other suitable liquid topassage 52 and ventingpassage 54. This causespiston 16 to move to the left and because of the helical splined connections tohousing 12 androtor 14 causesrotor 14 to rotate.

Whenpin 60 reaches the opposite end ofgroove 62 further rotation of rotor is stopped andpiston 16 is then in its leftmost position. In theposition tube 38 connects from port 56' toport 58b and tube 38' connects fromport 56 toport 58c.

To reverse the operation,passage 52 is vented and motive fluid is supplied topassage 54. This causespiston 16 to move to the position illustrated in FIG. 4.

Flow line switch 100 as shown in FIG. 7 is a modified form of the present invention.Switch 100 includes housing 102 formed bybody 104 andend closure 106 secured thereto bystuds 108 andnuts 110,rotor 112 andannular piston 114 positioned and adapted to reciprocate in theannular space 116 betweenrotor 112 andbody 104.Rods 118 secured in housing 102 extend throughpiston 114 and form guides on whichpiston 114 slides to prevent it from rotating.

Rotor 112 includessleeve 120,end plates 122 and 124 andcurved tube 126 extending fromport 128 inend plate 122 toport 130 inend plate 124. The exterior ofsleeve 120 has helical splines 132 which engage thesplines 134 on the interior ofpiston 114 so that longitudinal movement ofpiston 114 causesrotor 112 to rotate whereby communication is established betweenduct 136 and one ofducts 138 and 140 depending on the position ofcurved tube 126. The alternate position oftube 126 when connecting to port 131 and toduct 140 is shown in dashed lines in FIG. 7.Screws 142 and 144 withlock nuts 146 and 148 thereon extend into the ends ofannular space 116 to provide stops limiting the movement ofpiston 114.

Switch 100 shown in FIG. 7 is operated by supplying motive fluid tospace 116 on one side ofpiston 114 while venting the space from the other side through suitable passages (not shown). The pressure of fluid on the right side ofpiston 114, as shown in FIG. 7, causes it to move to the left until it reaches thestop 144. Sincestop 144 is preset to control the length of stroke ofpiston 114,rotor 112 is turned to the position shown in dashed lines so thatduct 136 is connected throughtube 126 and port 131 toduct 140.Rotor 112 is rotated by its helical splined connection topiston 116 sincerods 118 preventpiston 116 from rotating.

Return ofrotor 112 to its original position is accomplished by supplying motive fluid inspace 116 on the left side ofpiston 114 and ventingspace 116 on the opposite side.Pin 142 stops the movement ofpiston 114 to assure proper registry oftube 126 withport 130 and in communication withduct 138.

Claims (14)

What is claimed is:

1. A flow line switch comprising

a housing having an internal cylindrical chamber,

at least one passage communicating through the housing into one end of the chamber,

at least two passages communicating through the housing into the other end of the chamber,

a rotor positioned within the chamber against the ends thereof and having an exterior cylindrical surface spaced from the interior cylindrical surface of the housing to form an annular space and a tube extending through the rotor to communicate between the ends of the chamber,

an annular piston positioned within said annular space,

means for introducing an actuating fluid into either end of said annular space to cause the piston to reciprocate therein, and

means connecting the piston with the rotor and the piston with the housing so that movement of the piston in one direction rotates the rotor and movement of the piston in the opposite direction reverses the direction of rotation of the rotor whereby the tube provides a change of communication between the housing end passages.

2. A flow line switch according to claim 1 wherein said connecting means includes

a helical spline connection between the piston and said rotor, and

means connecting between the piston and the housing to assure that movement of the piston causes rotation of the rotor to rotate.

3. A flow line switch according to claim 2 wherein said connecting means between the piston and the housing includes

a helical spline connection.

4. A flow line switch according to claim 3 including sealing means on the piston for sealing the splines to prevent leakage of operating fluid past the piston.

5. A flowline switch according to claim 2 wherein said connecting means between the piston and the housing includes

at least one rod extending axially through said annular space and through the piston.

6. A flow line switch according to claim 5 wherein only a single tube extends through the rotor to communicate between said end passages.

7. A flow line switch according to claim 1 including

means for limiting the rotation of the rotor responsive to the movement of the piston to assure registry of the rotor passageway with the preselected housing passages at each end of the movement of the piston.

8. A flow line switch according to claim 7 wherein said rotor limiting means includes

at least one stop pin mounted in the housing and projecting into a semi-annular groove in the end of the rotor.

9. A flow line switch according to claim 7 wherein said rotor limiting means includes

a pair of adjustable stops positioned one in each end of said annular space.

10. A flow line switch according to claim 9 wherein

said stops extend through the housing and are threaded therein for adjustment of the stopping positions of the piston.

11. A flow line switch according to claim 1, including

means for equalizing pressure between the interior and the exterior of the rotor.

12. A flow line switch according to claim 1, including

a sleeve in each of the housing passages,

means for resiliently urging each sleeve into sliding engagement with the rotor ends and to seal around the rotor passage when it is in registry with said sleeve.

13. A flow line switch according to claim 1 wherein said piston includes

a body ring,

packing rings on each side of said body ring, and

means for retaining said rings assembled.

14. A flow line switch according to claim 1 including

two housing passages communicating into said one end of the chamber,

four housing passages communicating into said other end of said chamber, and

a pair of tubes extending through the rotor to communicate between said end passages.

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